Floating piston plant



y 1938- v H. STEINER 2,115,921

FLOATING PISTON PLANT Filed March 8, 1935 3 Sheets-Sheet 1 w a/ I I nun 8o 29 m l fly, 27 n u u u I I am I //a 22 2.; 22

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May 3, 1938.

H. STElNER FLOATING PISTON PLANT s Sheets-Sheet 2 Filed March 8, 1935 .ml m,

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May 3, 1938.

, [Iii H. STEINER FLOATING PISTON PLANT Filed March 8, 19 55 5 Sheets-Sheet 3 Patented May 3, 1938 UNITED s'ra'rss FLOATING PISTON PLANT am .Steiner, Winterthur, Switzerland, assignor to Sulaer Freres, Societe Anonyme, Mnterthur,

- Switzerland Application March 8, 1935, Serial No. 10,081

In Switzerland March 13, 1934 The present invention relates to a united reciprocating internal combustion engine and compressor of the floating piston type having a plurality of power and compressor cylinders for gen- 5 crating hot high pressure gases which may be used for operating, for example, a'gas turbine and for producing compressed air which is used as combustion air in said apparatus. and/or may also be used for other purposes, more particularly to methods and apparatus for synchronizing the operation of the individual pistons and for controlling the stroke of the individual pistons.

An object of the present invention resides in the provision of a hook-up between the pistons operating in different cylinders of a united reciprocating internal combustion engine and compressor having floating pistons, whereby, at a change of the length of the stroke of the pistons operating in one cylinder, the length of the stroke of the pistons operating in another cylinder is -automatically changed, too.

A further object of the present invention is the provision of a hydraulic or pneumatic coupling between pistons operating in diflerent cylinders of a united reciprocating internal combustion engine and compressor, whereby the length of the stroke of various floating pistons operating in different cylinders can simultaneously be changed a by adding operating medium to or by withdrawing it from the hydraulic or pneumatic coupling.

Another object oi this invention is to provide a hydraulic or pneumatic coupling between pistons operating in diflferent cylinders of a united reciprocating internal combustion engine and compressor, whereby the length of the stroke of various floating pistonsoperating in different cylinders is automatically maintained by automatically adding operating medium to or by with-- 40 drawing it from the hydraulic 'or pneumatic coupling.

A further object of this invention is the provision of an engine having floating pistons, the end of the stroke of which is determined by the pressure of a medium compressed in the clearance of the cylinders in which the floating pistons operate, and of supplementary cushioning means adapted to check the movements of the floating pistons and to adjust their position at the end of a stroke.

A further object of this invention is to provide a unifled internal combustion-compressor engine having floating pistons and in which the power and compressor pistons are directly connected and in line with one another and in which also the power and compressor cylinders are 'direct-.

ly connected and in line with one another, and of means assuring that, when the stroke of a combined power and compressor floating piston is changed, the stroke of the power piston is in Fig. 4.

changed to a length diflerent from that of the compressor piston. v

Ah object of this invention-is the provision of a unifled internal combustion-compressor engine having floating pistons comprising a plurality of.

unified power and compressor cylinders and a coupling adjustably interconnecting the floating pistons operating in diflerent cylinders and adapted to change the stroke of the pistons operating in diiferent cylinders in dependence on an operating characteristic of said unified internal combustion-compressor'engirie.

Further and other objects of the present invention will be hereinafter set forth in the accompanying speciflcation'and claims and shown in' the drawings which, by way of illustration, show what I now consider to be a preferred embodiment of my invention.

In the drawings:

Fig. 1 is a diagrammatic showing of a' power and compressed air producing plant according to my invention.

'Fig. 2 is a crank diagram of an engine as illustrated inFig. 1.

Fig. 3 is another crank diagram as showninFig. 1.'

Fig. 4 is a diagrammatic showing of another embodiment of my invention. I

Fig. 5 shows a variation of the plant illustrated of an engine Fig. 6 is a diagrammatic showing of a deta of the plant illustrated in Figs. 4 and 5.

Fig. 'I is a diagrammatic showing of a variation of the detail shown in Fig. 6.

Fig. 8 shows indicator diagrams of engines according to my invention and forming the principal part of the plants shown inFigs. 1, 4, and 5.-

Fig. 9 shows another variationof the plant shown inFig. 4.

Like parts are designated by like numerals in all figures of the drawings.

Referring more particularly to Fig- 1 of the drawings: l and 2 are the power pistons operating within combustion cylinder 5; '3 and l are power pistons operating within combustion cylinder 6. To the ends of combustion cylinder 5,

compressor cylinders'l and 8 are attached and, Y to the ends of combustion cylinder 6,-compressor cylinders 9 and ll. Compressor pistons il,

l2, I3, and M are connected to the powerpistons I, 2, 3, and 4, respectively. Combustion and scavenging air is conducted into cylinder 5 through conduit i5 and into cylinder 6 through conduit I5. Fuel is introduced into cylinder; 5 through feeder l! andinto cylinder 5 through feeder l8. These feeders are not shown in detail as they are not part of the present invention.

'The exhaust gases of cylinder 5 are removed through conduit i9 and those of cylinder 6 through conduit 20'. Both conduits may be conscavenging air.

nected to a conduit 39 which conducts the exhaust gases of cylinders 5 and 9 into a gas turbine 90. The gas to be compressed, for example air, is drawn into single acting compressor cylinders I and 9 from filter 89 through duct 2| and into single acting compressor cylinders 3 and In from filter 8| through duct 2|. The air compressed in cylinder 1 passes through duct 22 into receiver 82 and therefrom through conduit l5 into cylinder 5 serving as charging and Likewise, the air compressed in cylinder 9 passes through conduit 22' into receiver 83 and therefrom through conduit it into cylinder 6. The air compressed in cylinders 8 and I0 passes through conduits 94 and 95 into common receiver 89 and therefrom to consumers, for example, pneumatic hammer 91 and/or compressed air turbine 98.

A rod 23 is connected to compressor piston II, a rod 25 to piston l3, a rod 24 to piston l2, and a rod 26 to piston l4. These piston rods are each movably connected with a connecting rod,-name- 1y, 23 with 21, 25 with 29, 24 with 28, and 26 with 30. Connecting rods 21 and 29 operate crank shaft 3|, and connecting rods 29 and 30 operate crank shaft 32. The individual cranks on-each shaft and the cranks of two different shafts but Fassociated withthe same cylinder are set at an angle of 180 with respect to one an:- othersothatthe pistons associated with the cranks move in opposite directions. The radius of the cranks maybe made so large as compared with the stroke of the pistons that the crank shafts do-notrotate-but carry out a swinging motion, whereby the cranks never reach the crank dead center position proper. Crank shafts 3| and32 may be coupled together by means of bevel gears I09, ill and H0, H2 and shaft H3 arranged between these gears, whereby the countermovement of the-pistons in the individual cylinders is synchronized.

It is of advantage to make the length of the connecting rods as small as possible as compared with the radius of the associated cranks because, with such a construction, a change of the position of a power piston at the end of its compression stroke entails only little change of the position at the end of the compression stroke of the associated compressor piston. This is obvious from Fig. -2. If the swing of the crank shaft is reduced from angle a to angle 3, the stroke of the unitedpower and compressor piston is reduced from value a to value b; the position of the power piston at the end of its compression stroke is changed by thedistance d, whereas the position of the compressor piston at the end of its compression stroke is changed by the shorter distance 0. The shorter the connecting rod, the greater is the difierence between d and c. In this way, even a great change of the position of the power pistons at the end of their compression stroke has but little effect on the position of the associated compressor pistons at the end of their compression strokes and has but little effect on the pressure of the gas compressed in the compressor cylinders. Fig. 3 diagrammatically shows an arrangement in which the crank passes outer dead center position, and the connecting rod 28 moves on both sides of the center line of the cylinder so that, for each position of the piston, two positions of the connecting rod are possible, whereas, in the arrangement shown in Fig. 2, the. connecting rod 28 moves always on one side of the center line of the cylinder, and only one position of the connecting rod is'possible for each position of the piston. For an operation according to the diagram Fig. 3, the crdnk shafts 3l' and 32 are provided with fly wheels 'l22-and I23 so that the crank shafts swing beyond dead center position as diagrammatically shown in Fig. 3. If the extent of the swing of a shaft is reduced from the value 7 in Fig. 3 to value 6, the inner dead center position of the piston associated with this crank is changed by the distance 2, whereas the outer dead center position is not changed at all.

The operation of the apparatus according to Figs. 1 and 3 is as follows:

If more power is required from gas turbine 99, more fuel is supplied through nozzles I'l and H3. The supply of fuel may be adjusted by hand or automatically; this adjustment per se is not part of the present invention. An increased fuel supply to cylinders 5 and 5 causes increased pressure within these cylinders and a shortening of the compression stroke of the power pistons. Before the increase of fuel supply, shaft 32 swings, for example, as far as angle 7 in Fig. 3; after the increase of the fuel supply, the shaft only swings as far as the smaller angle 6 in Fig. 3, and the stroke of a combined power and compressor piston is decreased by the distance e,

v and the. space available for combustion is in creased accordingly. The work done per stroke of av power piston is thereby considerably increased as is obviousfrom and will be described later in connection with the diagram Fig. 8. As

soon as more power is available from the power pistons, the movement of said pistons is sped up-and more compressed per time unit; as long as the consumption of gases produced in the combustion cylinder and/or the amount of compressed air required for purposes other than combustion purposes is not increased, higher pressure in the air compressors associated with the combustioncylinders and of the charging and scavenging air is obtained automatically. As is also obvious from the diagrams Fig. 8, a shortening of the suction stroke of the air compressor pistons is of little influence on the air pressure obtained, and it is desirable to maintain the outer dead center position of the associated pistons I, ll, 2, l2, 3, l3, and 4, I4 andto arrange for wide variations of the inner dead center positions in order to obtain highest efliciency in the operation of the power part aswell as of the compressor part of the engine. This condition is assured by a machine according to Fig. 1 of the drawings to a great extent if operated according to Fig. 3 and, to a modified extent, if operated according to Fig. 2.

In the embodiment of my invention illustrated in Fig. 4 of the drawings, the pistons are pair-wise interconnected by means of a combined hydraulic and mechanical coupling. As far as the power cylinders and power pistons and the compressor cylinders and compressor pistons are concerned, the arrangement is the same as the one shown in Fig. 1. The compressor piston ll carries, by means of an extension rod 35,,an auxiliary piston 35; in like manner, piston l3 carries auxiliary piston 38; piston l2 carries piston 31 by means of rod 35, and piston i4 carries auxiliary piston 39 likewise. A conduit 33 containing a liquid or gaseous operating medium connects pistons 36 and 38, and a conduit 34 also carrying a liquid or gaseous operating medium operatively connects pistons 31 and 39. Control device 49 is arranged in conduit 33 and a like device 4| in conduit 34; the purpose of said devices is to control addition of operating medium to and withdrawal of operating medium from conduits 33 and 34. Pistons 33 and 33 each carry a piston rod 33' and 33', respectively, the' ends of which are individually movabiy connected tovthe ends of two-arm lever'42. The fulcrum 44 in-the center of lever 42 is carried by slide valve 43. Likewise, pistons 31 and 33 carry two-arm lever 43, (the fulcrum 45 of which is carried by slide valve ll. Valve 46 moves within cylinder II having ports 48, 49, and 33. Cylinder 3| slidably moves within the cylindrical casing of device 43 against the tension of spring 32 and under the action of a control fluid introduced through conduit". A like cylinder is provided in control device-4i which may be actuated by a control fluid introduced through conduit 33'. Conduits 33 and 33' are connected by means of conduit 'I l4 withthe air chamber supplying 'the inlet ports III of cylinder 3 with scavenging and combustion The operation of cylinders 3| is thus made dependent upon the pressure of the charging and scavenging air. 1

If the pressure of the scavenging and charging air goes up, valve cylinder 3| is moved.upwards as viewed on Fig. 4-;1 openings 43 and 33 are then free, and coupling contained in conduit 33 exits through outlet I3:; 'pistons I II and 3, I3 thereioremove further outwards,.whereby the clearance in cylindersil and 3 is reduced, and the volume available for air compression in said cylinders is reduced; causes .a decrease of the pressure oi the charging and scavengingair-aresult which was desired.

The outward movement of pistons I, II, 33.

and 3, I3, 33 also causes an outward movement of valve 43, whereby opening 33 is closed again so that equilibrium is restored and outflow of too much medium out of conduit 33 is prevented.

If the pressure in chamber II3 decreases, piston 3| moves downwards-411s viewe'din Fig; 4- and opening 33 is closed, whereas opening 43 is opened permitting an inflow of medium through conduit 34 into conduit 33; p tons 33 .and 33 are pressed downwards-as viewed in Fig. 4-andtherewith piston sets I, II and 3, I3; this causes an increase of the clearance in cylinders I and 3 .eration of cylinders 3| and the adjustment of.

the length of the columns of liquid in conduits 33 and 34 are madedepe'ndenton the m pressure ofcylinderl.

The operation of the arrangement according to- Fig. 5 is like the operation described in connectionwith' Fig. 4, .with the exception that whereasby the arrangement according to Fig. 4 the pressure of scavenging and charging air entering cylinders 3 and 3 is maintained constant, in the arrangement according toPig. 5 the-pressureof the gases leaving cylinders 3'and 3 is maintained.

The extent of the movement of cylinder 3I may be limited and manually adjusted by operating spindle II3 extending throughcover II3 of body 40 and having a hand wheel I23. A similar adjusting means H3 and I33 may be associated with control device 4I. These manual adjusting means may serve solely for adjusting the length of the columns of conduits 33 and 34 or may be used in connection with the pressure control actuated by the fluid pressure in conduits 33 and 33'.

When operating the floating piston power plant, the/pistons in cylinders .3. and 3 are alternately driven apart imder the influence of the expanding combustion gases; and air is simultaneously compressed in cylinders I, 3, 3. and I3. The air-compressed in cylinders l and 3 goes through conduits 33 and 33 into receiver 31 and therefrom as co|n-. bustion and scavenging air through conduit I3 into power cylinder 3. The air compressed in cylinders 3 and III goes through conduits 33 and 33 into receiver I33 and therefrom as combustion and scavenging air through conduit I3 into cylinder 3. The combustion gases leave cylinder 3 after expansion therein through conduit III and are further used vto drive the gas turbine I33. The gases exhausting from cylinder 3 are likewise conducted through conduit I32 into, a turbine I34. Conduits III and I32 may be interconnected, by tube line I33 having a stop valve I33 for separating or interconnecting conduits III and I32. In the arrangements shown in Figs. (and 5, much-more air may be supplied to the power cylinders than is neededfor burning up the fuel. A part'of the air, therefore, passes through cylinders 3 and 3 and serves for cooling the exhaust gases, whereby thelife of the gas turbines is prolonged and their eiilciency increased.

The movement of the pistons is checked in the extreme outer positions by the pressure of the air cushions created during the outward movement of the pistons. At the following periodof operation, the pistons are moved back pairwise into center positionby the action of the piston pair which carries out an expansion stroke, said action being transmitted through the medium in conduits '33 and 34. At an inward movement'of the compressor pistons, air is drawn into the com- =pressor cylinders from conduits 2| and II. At

the same time, the scavenging air and combustion air entering cylinders 3 and 3 through conduits I3 and I3, respectively,v is compressed by action of the power pistons moving towards the center of their cylinder. The expansion of the gases resulting from the combustion of the fuel introapart, and the cycle 0! operation starts anew.

The stroke of the power and compressor pistons depends on the extent to which conduitsf'33 and 34 are fllied'with operating medium. This filling is controlled by means 01' the devices 43 and 4| as has been described before. 7

In order to also synchronize the movement oi the pistons countermoving in the same cylinder, a double acting piston 33 may be introduced into conduit 33 and a similar piston. into conduit operate pistons 33 and 3|, respectively.

Pistons-33 and 3I- areadapted to reciprocatlngly move In cylinders 33 and 33', respectively which orln part of the conduit and are operatively duced through feeders I1 and I3 drives the pistons I terconne'cted by a gaseous or liquid medium enclosed in conduit 32. One of the cylinders 33 and 33' in the case illustrated, cylinder 33- points in the direction of piston 33. while the "other'points in opposite direction giving conduit 33 'with its cylinders 33 and 33" the configuration of a Z and'assuring that both pistons 33 and 3| move in the-same direction, whereas pistons I and 2 and also pistons 3 and 4 move in opposite directions.

A relief valve 34 may be provided 13 'into the combustion cylinders.

in connection with conduit 92 which allows operating medium to escape if the pressure within conduit 62 is too high, for example, when a piston 60 or 6| gets jammed and the other piston is still in motion. Furthermore, a conduit 65 with a check valve 66 may be provided through which supplementary operating medium may be supplied to conduit 62 to make up leakage losses and the like. Should the provision of conduit 62 in connection with single acting pistons 60 and 6! not suflice to assure a rigid and positive synchronizing action, a conduit 62' may be provided to interconnect the other sides of pistons Ell and SI and also be filled with operating medium; such a conduit would assure an absolutely rigid operation.

If the gas cushion in the compressor cylinders is not sufiicient to limit the stroke of the pistons, an additional hydraulic damper may be associated with each of the pistons 36, 31, 38, and 39 by providing. each piston with an extension 61 which, at the end of an outward piston stroke, is inserted into a corresponding recess 69 of plug 68 extending into the interior of conduit 33. The operating medium contained in recesses 69 is f compressed to a certain degree which depends,

for example, 'on the amount of fuel introduced If much fuel is introduced, the pistons are thrown outwards with great force, and piston 3! creates great pressure in recess 69, operating medium may escape, and the pressure be relieved through a conduit 10. Such a damper is illustrated in larger scale in Fig. 6 of the drawings. Conduit III permits constant leakage of operating medium; the bore of said conduit is very small as compared with the size of chamber 69, and the amount of leakage is very small; as soon as larger amounts pass through conduit 10, the velocity of the fluid and the fric- 69, larger amounts are pushed through channel 10 and this is desirable because in this manner excessive pressure in chamber 69 is relieved. A pressure relief valve may be connected to conduit 18 which thencan have a larger bore.

When more work is done in cylinders 5 and 6 because of an increase of the interior volume and capacity of the cylinders caused by an outward movement of the outer dead center position of the pistons, it may be necessary that the clearance in the compressorbe reduced so that its capacity increases; this is particularly important if it is desired that the pressure of the compressed gas or air remain constant.- For this purpose, a damper as shown in Fig. 7 may be provided for the pistons 35, 31, 38, and 39 in Fig. 4which'are each provided with an extension ll and which, I

can be changed by adapting cages 12 to be moved in the direction of the axes of pistons 36, 31, 38, or 39, respectively- Such change of position of cages 12 can be eifected by providinga thread ll in the upper center part of cage 12 which also serves as a-gland for the rods connecting pistons 35, 31, 38, and 39 with the double levers 42 and 43, as was previously described, and by also threading the part pertaining to conduit 33 or 34, shown in Figs. 4, 5, and 9, adjacent to said center part, so that cage 12 may be screwed up and down. A channel 15 may be provided in cage 12 corresponding to channel ID in Fig. 6 for relieving the operates in the same manner as does the channel 19 in Fig. 6. A pressure relief valve 15' may be provided to act in the same manner as valve 10 of Fig. 6.

The operation of an arrangement according to Figs. 4 to '7 with respect to the dead center positions of the pistons is like the operation of the arrangement according to Fig. 1 and operating as per diagram Figs. 2 or 3. Whereas in the arrangement according to Fig. 1 theouter dead center positions of the pistons are little or not at all changed, at a change of the inner dead center positions due to-the particular swinging motion demonstrated in Figs. 2 and 3 the outer dead center positions of the pistons in arrangements according to Figs. 4 to 'I are held substantially constant because the outward movement of the pistons is positively terminated by the air compressed in the compressor cylinders and/or the medium compressed in chambers Q9 and I3.

In order to demonstrate the effect of a change a of the inner dead center positions and the maintenance of the outer dead center positions of the pistons in the arrangements according to Figs. 1 to 7, diagrams Fig. 8 have been plotted.

The upper part of Fig. 8 shows indicator dia grams of the combustion cylinders 5 and 6. The dotted line diagram shows the conditions with far inwards moving pistons as is the case when is the case when shaft 32 swings around angle p in Fig. 2 or angle 6 in Fig. 3. Charging pressures and compression pressures are high and the combustion volume V1 amounts to 13% ,of the total expansion volume.

The lower part of Fig. 8 shows two indicator diagrams of the compressors corresponding to the operating conditions of the power pistons shown in the upper part of Fig. 8. In both cases, the compression volume Vc is approximately the same, whereas the compression pressurein the case of the dotted line diagram-amounts to 1.2 atmospheres'and-in the case of the solid lin diagram-amounts to 4.0 atmospheres.

The upper diagrams of Fig. 8 which represent indicator diagrams taken in the combustion or power cylinders show that an increase of the combustion'space at the inner dead center position of the power pistons together with an increase of the fuel supply greatly increases the work per stroke of the power pistons which is represented by the area enclosed by the indicator diagrams;

the work available for air compression is, of

course, also increased; the lower diagrams of Fig.

8 which represent indicator diagrams taken in the air compressor cylinders show that a change of the inner dead center position-which is represented by the left side of Fig. 8of the air compressor piston has little effect on the work required by the compressor which is represented by the area .enclosed' by the indicator diagrams, whereas, for example, an outward movement of the outer dead center position of the air compressor pistons would greatly increase the area In the embodiment of my invention according to Fig. 9, valve cylinders 5| inside of control means ,43 and 4| and illustrated in Fig. 4 are made responsive to the amount of fuel supplied to power'cylinder 6, and the fuel injection is made dependent on the charging pressure of the power cylinder and also on the stroke of a floating piston. For the latter purpose, compressor piston I3 carries a bolt I24 which abuts, at the end of an inward stroke of the piston, against one arm of bell crank lever I25. The other arm of this lever .is adapted to adjustingly abut, by means of adjusting screw I40, against the end of lever I to which fuel valve I26 is connected. Upon abutment of lever I25 against lever I4I,' the fuel valve is lifted against the action of spring I42, and fuel oil supplied by rotary pump I28 isadmitted to cylinder 6. When valve I26 is closed, the .fuel oil passes-through constant pressure relief valve I36 and conduit I29 back into tank I32. The extent of the fuel admission stroke of valve I26 is further controlled in dependence on the pressure of the scavenging air in chamber I33. For this purpose, chamber I33 is connected by conduit I34 with cylinder I35 containing piston I36-which may be moved downwards, as viewed in Fig. 9, by action, of the pressure of the scavenging air and against the action of spring I3I. A rod 64' is connected to piston I36 and movably carries arm I3I, to the free end of which eccentric I33 forming the fulcrum of bell crank lever I25 is connected. Fuel injection is advanced or retarded according to the position of eccentric I33. The stem of valve I26 carries a piston I43 operating in cylinder I44, the interior of which is connected with the interior of casings 40 and 4| by means of conduits I45, 53, 'and 53'. These conduits and the cylinders connected thereto are filled with an actuating medium, for example, air which transmits movements of piston I43 to valve cylinders 5|. In this manner, the position of cylinders 5| is made dependent on the position of valve I26, 1. e., if this valve is lifted to a great extent, cylinder 5| is also lifted to a great extent; the more dense the operating medium in conduits 53, 53, and I45, the

more pulsating will be the operation of cylinder 5|; the extent of movement, however, is always in proportion to the extent of the opening of fuel valve I26 and the movements of cylinder 5| are thus made dependent on the amount of fuel supplied to power cylinder 6. I

For example, if more power is required. from gas turbine I64, more operating gas is demanded from and the pressure in cylinder 6 goes down upon withdrawal of -more gas therefrom; as a result piston 3, I3 will move further inwards and, with it, pin I24; this causes an increase of the stroke of fuel valve I26, .of the fuel supp y to cylinder 6, and of the pressure and amount of gas produced to operate turbine I04. A decrease of the back pressure in cylinder 6 also causes an upward movement of piston I36as viewed on of port and permitting an outflow of operating medium from conduit 33 through ports 43 and '53 and conduit 65. This reduction of the content of conduit 33 entails also a lifting-as viewed. on

Fig. 9of fulcrum 44 and valve 46 and a closing of port 54, whereby equilibrium is restored.

'While I believe the above described embodiments of my invention to be preferred embodiments, I wish it to be understood that I do not desire to be limited to the exact details of method,

design, and construction shown and described,

7 for obvious modifications will occur to a person skilled in the art. I What isclaimed is:

1. In a united reciprocatingpower and comsaid power-cylinder and being adapted to automatically change the position of said piston 7 within said cylinder in dependence on the pressure conditions within said cylinder and for the purpose of changing the space available for-combustion in said cylinder in dependence on the pressure conditions of the air supplied to said cylinder and for maintaining said pressure.

2. In a united reciprocating internal combustion and compressor engine; a plurality of cylinder units, each unit comprising a compressor and a power cylinder, a floating piston operating in each of said cylinder units and comprising a power pistonoperating in said power cylinder and a compressor piston operating in said compressor cylinder, means interconnecting the floatin pistons of two different cylinder units and adaptedto assure countermovement of the interconnected pistons and .comprising means for changing the position of said interconnected floating pistons at the outer dead center position thereof to a smaller extent than the position is changed at the inner dead center position when the forces acting on said pistons are changed.

3. In a united reciprocating internal combustion and compressor engine, a plurality of cylinder units, each unit comprising a power cylinder extending at both ends into a compressor cylinder, a pair of floating pistons operating in each of said cylinder units, and hydraulic couplings connected to all of said floating-pistons and pairwise interconnecting those of saidfloating pistons which are in different cylinder units and those-of said floating pistons which are in the same unit for assuring true'countermovement of the interconnected pistons.

4. In a united reciprocating internal combustion and compressor engine, a plurality of cylinderunits, each unit'comprising a compressor and a power cylinder, a floating piston operating in ch of said cylinder units and comprising a power piston operating in said power cylinder and a compressor piston operating insaid compressor cylinder, a hydraulic coupling containing an operating medium interconnecting the floating pistons of at least two different cylinder units,pressure responsive means connected with coupling and at least one of said cyllnderunits and being adapted to increase the content of operating medium of saidcoupling and to thereby si-I multaneously mo said interconnected floatingpistons further decrease the con of operating medium of said coupling and to thereby simultaneously move said interconnected floating pistons further into saidcompresaor cylinder orthepurpose of increasing and decree-dug available ior comlmsiion in said power cylinder for obtaining best operafing eillciency at all load conditions and for controlling the movements of said floating pistons and assuring safe operation.

5. In a united reciprocating internal combustion and compressor engine, a plurality oi cylinder units, each unit comprising a compressor and a power cylinder, a floating piston operating in each of said cylinder units and vcomprising a power isten operating in said power cylinder and a compressor piston operating in said compressor cylinder, a hydraulic coupling containing an operatlng medium interconnecting the floating pistons oi at least two difierent cylinder units, pressure responsive means connected with said coupling and at least one of said cylinder units and being adapted to increase the content of operating medium of said coup ng and to thereby simultaneously move said interconnected floating pistons further into said power cylinder and to decrease the contents of operating medium of said coupling and to thereby simultaneously move said interconnected floating pistons further into said compressor cylinder for the purpose of decreasing andjncreasing the space available for combustion in said power cylinder for obtaining best operating efllciency at all load conditions and Iorcontrolling the movements of saidfloating pistons and assuring safe operation, and control means movably associated with said pressure responsive means and movably connected with said interconnected floating pistons and being also adapted to increase and decrease the content of operating medium of said coupling and to thereby counteract the action of said pressure responsive means and prevent excessive change of position of said interconnected floating pistons.

6. In a united reciprocating internal combustion and compressor engine, a plurality of 'cylinder units, each unit comprising a power cylinder extending at both ends into a compressor cylinder, a pair of floating pistons operating in each of said cylinder units, and hydraulic couplings interconnecting those of said floating pis-;

tons which are located in different cylinder units for synchronizing their movements, and other bydraulic couplings interconnecting those of said floating pistons which make up one pair and operate in the same cylinder unit for assuring true coimtermovement of said floating pistons which are in the same cylinder unit.

7. In a united reciprocating internal combusflon and compresor engine, a cylinder unit comprising a power cylinder and two compressor cylinders connected thereto, a pair of floating pistons located in said cylinder unit, each floating piston comprising a compressor piston operating in one of said compressor cylinders and a power piston operating in said powercylinder, and a hydraulic coupling interconnecting said floating pistons for synchronizing and assuring true countermovement of said floating pistons.

8. In a united reciprocating internal combustion and compressor engine, a central combustion cylinder extendixat both ends into a compressor cylinder, a pair of countermoving floating pistons operating in said cylinder, each floating piston comprising a compressor piston operating in one of said compressor cylinders and a power piston operating in said combustion cylinder,-

valve means attached to said compressor cylinders and adapting said compressor pistons to carry out a compression stroke while said powerpistons carry out an expansion stroke, means operatively connected to said floating pistons and being adapted to automatically change the position of said floating pistons at the end of the compression stroke of said compressor piston to a smaller extent than the position of the asso ciated power piston is changed at the end of the compression stroke of said power piston when the forces acting on said pistons are changed.

9. In a united reciprocating internal combustion and compressor engine, a combustion cylinder extending at one end into a compressor cylcrease of the pressure of the medium compressed in said compressor cylinder for maintaining the pressure of said medium. 7

10. In a united reciprocating power and compressor engine, a power cylinder extending at one end into a compressor cylinder, a floatingpiston in said cylinder, said floating piston comprising" a compressor piston operating in said compressor cylinder and a power piston in said power cylinder, pressure responsive means operatively associated with said floating piston and said power'cylinder and being adapted to automatically move said floating piston further into said compressor cylinder upon an increase of the pressure in said power cylinder'and further out 01' said compressor cylinder upon a decrease of the pressure in said power cylinder for controlling the pressure conditions in said power cylinder.

11. In a united reciprocating internal combustion and compressor engine, a combustion cylinder extending at one end into an air compressor cylinder, a floating piston in said cylinder, said floating piston comprising a compressor piston operating in said compressor cylinder and a power piston in said combustion cylinder, an air conduit connecting said compressor cylinder and said combustion cylinder, pressure responsive ,means operatively associated with said floating piston and adapted to automatically move said floating piston further into said compressor cyl-, inder upon an increase of the pressure of the combustion air supplied to said combustion cylinder and further out of said compressor cylinder upon a decrease of the pressure of the combustion air supplied to said combustion cylinder for controlling the combustion air pressure and the movement of said floating piston.

12. In a united reciprocating power and compressor engine, a power cylinder extending at one end into a compressor cylinder, a floating piston in said cylinder, said floating pistoncomprising a compressor piston operating: in said compressor cylinder and a power. piston in said power cylinder, an exhaust-conduit connected with said power cylinder, pressure responsive means operatively associated with-said floating piston and said exhaust conduit and being adapted .to automatically move said floating piston further into said compressor cylinder .upon an increase of the pressure-of the medium leaving said power cylinder and further out of said compressor cylinderupon a decrease of the pressure of the medium leaving said power cylinder for controlling the pressure of the medium leaving said power cylinder.

13. In a united reciprocating internal combustion and compressor engine, a combustion cylinder extending at one end into a compressor cylinder, a floating piston in said cylinder, said floating piston comprising a compressor piston operating in said compressor cylinder and a power piston in said combustion cylinder, means adapted to substantially maintain the position of said pistons at the end of the compression stroke of said compressorpiston when the position of said floating piston at the other end of its stroke is changed due to a change of the forces acting on said floating piston for substantially maintaining the clearance insaid compressor cylinder independent of changes of the position of the power piston at the end of the compression stroke of said power piston.

14. In a united reciprocating internal combustion and compressor engine, a combustion cylinder extending at one end into a compressor cylinder, a floating piston in said cylinder, said float-' ing piston comprising a compressor piston operating in said compressor cylinder and a power piston in said combustion cylinder, means adapted to adjustably maintain the position of said pi tons at the end of the compression stroke of said compressor piston when the position of said floating piston at the other end of its stroke is changed due to a change of the forces acting on said floating piston for adjustably maintaining the clearance in said compressor cylinder independent of changesof the position of the power piston at the end of the compression stroke of said power piston.

15. In a united reciprocating internal coni bustion and compressor engine, a plurality of cylinder units, each unit comprising a compressor and a-power cylinder, a floating piston operating in each of said cylinder units and comprising a power piston operating in said power cylinder and a compressor piston operating in said compressor cylinder, said compressor piston carrying out a compression stroke when the power piston directly associated therewith makes 'an expansion stroke, means interconnecting the floating pistons oi a plurality-of different units and adapted to assure countermovement" of the interconnected pistons and'to transmit the power of a power piston which is not used up by its associated compressor piston to the interconnected floating pispistons at the outer end of their strokes when ton said means comprising means adapted to substantially maintain the position of said floating the position of said pistons is changed at the inner end of their strokes due to a change of the forces acting on said pistons for the purpose-of substantially maintaining the clearance in all said compressor cylinders independent of variations of the end positions of said power pistons at the end of the compression strokes of said power pis-' tons.

16. In a'united reciprocating internal combustion and compressor engine, a plurality of cylinder units, each unit comprising'a compressor and a power cylinder, a floating piston operating in each of said cylinder units and comprising a power piston operating in said power cylinder and a compressor piston operating in said compressor cylinder, a hydraulic coupling containing an operating medium and interconnecting the floating pistons of at least two different bustion and compressor engine, a plurality of cylinder units, each unit comprising a compressor and a power cylinder, 9'. floating piston operating in each of said cylinder units and comprising a power piston operating in said power cylinder and a compressor piston operating in said compressor cylinder, a hydraulic coupling containing an operating medium which interconnects the floating pistons .of at least twodiflerent cylinder units, control means operatively connected with one of said cylinders and being responsive to the pressure therein and being adapted to increase the content of operating medium in said coupling upon a decrease of said pressure and to decrease the content of said coupling upon an increase of said pressure and to thereby simultaneously change the position ofthe interconnected floats ing pistons in dependence on the pressure in one of said cylinders for controlling said pressure and the operation of said floating pistons, and a two-arm lever operatively connected at its ends to and being oscillated by the floating-pistons interconnected by said hydraulic coupling and having a fulcrum which is carried by said means and is adapted to operate saidmeans for making said means also responsive to the position of said floating pistons for counteracting excessive actions of said control means.

, 18. In a united reciprocating internal combustion and compressor engine, a plurality of cylinder units, each unit comprising a compressor and a power-cylinder, a floating piston operating in each of said cylinder units and comprising a power piston operating in said power cylinder and a compressor piston operating in saidcompressor cylinder, a hydraulic coupling containing an operating medium which interconnects the floating pistons of at least two different cylinder units, control means operatively connected with one oi. said cylinders and being responsive to the pressure therein and being adapted to increase the content of operating medium of said coupling upon a decrease of said pressure and to decrease the content of said coupling upon an increase of said pressure and to thereby simul-- taneously change the position of the interconnected floating pistons in dependence on the pressure in one of said cylinders for controlling said pressure and" the operation of said floating pistons, said control means comprising means which are connected with and responsive to the movements of saidinterconnected floating pistons, said last mentioned means being adapted to counteract the actions of said control means and to prevent excessive action thereof.

HANS STEINER. 

